In order to explain away otherwise inexplicable phenomena
(or just due to a lack of better scientific education) Star Trek writers have
frequently introduced us to substances or particles which do not exist in the
real world -- or are not yet discovered or invented. Only few of these
substances or particles were used consistently. Many of them were mentioned only
once, and the next time a different exotic particle was responsible for a very similar
effect. Nevertheless, it is worth the effort to list all these substances or
particles, to attempt a classification and summarize their properties. This list
is strictly based on canon facts and therefore the
description of most items leaves more questions than it can answer.

The classification used in the following is not always
clear-cut. But usually we can notice the difference between particles (which
have some physical effect) and compounds (which have chemical or medical effects or are
used to build something). Also, something ending on -ium is obviously supposed
to be an element, whereas -(i)on usually stands for elementary particles. De
Broglie's particle-wave equivalence may save us from deciding between particles
and energy. Finally, the list
includes some real-world items too which are noted as such -- although some
particles in Star Trek behave very differently from their real-world cousins.

Chemical element
or isotope

Chemical
compound or alloy

Real-world
reference

Elementary
particle

Energy
field or radiation

Other
concept

A

Acetylcholine

Naturally occurring. Neurotransmitter. In real life,
also a neurotransmitter produced by the
brain.

TNG: "All Good Things" - Levels of
acetylcholine in the hippocampus can quantify the amount of memory an
individual has accumulated.

DS9: "Melora" - Bashir used a medication designed to increase
acetylcholine absorption to increase Melora's tensile muscular strength,
thus enabling her to walk.

VOY: "The Chute" - Increased amounts of acetylcholine in
Kim's nervous system caused him, like others in the prison camp, to exhibit
erratic violent behavior.

Acidichloride

Artificially generated by crew. Gaseous chemical. Toxic to humans,
essential to "evolved" humans. "Acidichloride" is the
official spelling of the Star Trek Encyclopedia. The substance has
previously been identified as "acid *di*chloride", which might stand for H2Cl2,
but such a molecule would break down into HCl (hydrochloric acid). Hydrogen
and chlorine combine 1:1, and chemicals tend to separate
into the lowest possible number of atoms. Acidichloride, in contrast, may be actually a short name of something
different, albeit it may be subject to confusion.

VOY: "Threshold" - The Doctor determines that the evolved
Tom Paris requires acid dichloride gas to breathe. This is quite
obviously scientific crap, because no species could undergo an evolution,
in whose course it breathes a gas that is poisonous to any living being.

Actinides

Naturally occurring.
Actinides are known to interfere with Federation sensors. Actin(o)ids: group of
radioactive elements in the 6th period of the periodic table of elements.

TNG: "The Mind's Eye" - The crew of the Enterprise
encountered these in the Ikalian asteroid belt. The actinides made it
difficult to locate the Kriosian rebels.

Adrenaline

Naturally occurring or artificially generated by crew.
A hormone used as a treatment for radiation damage. The real-life hormone.

TOS: "The Deadly Years" - Before
the invention of hyronaline, adrenaline was the treatment of choice for
radiation damage.

Ambizine

Artificially generated by crew. A narcotic used by
Starfleet, leads to unconsciousness.

VOY: "Before and After" - When Kes was irradiated with
chroniton particles from the Krenim and later subjected to a biotemporal
field, she began to shift backwards in time. This was cured by the use of an
antichroniton field.

Antigen

Artificially generated by crew. Destroys viruses. In
real medicine, a substance that triggers an immune response. May be natural or
synthetically produced.

VOY: "Macrocosm" - Janeway used an
antigen bomb against the macrovirus that had infected the ship. Well, a
microscopic antigen would hardly be of any use against scaled up
viruses...

Antigraviton

Artificially generated by aliens. Particle that
deflects transporter beams. In
real life, a graviton, a particle whose existence is only proven indirectly, is its own antiparticle. That is, an antigraviton would
actually be a normal graviton.

TNG: "Attached" - Was used by the
Prytt to
deflect a transporter
beam to a new set of co-ordinates.

Antilepton

Artificially generated by aliens. Antilepton
interference may prevent communications.
Antileptons actually exist, as a collective name for the antiparticles of
leptons.

DS9: "Emissary" - Gul Jasad's fleet flooded subspace with
antilepton interference. It doesn't sound very plausible that on one hand
the type of leptons can't be determined (or isn't worth mentioning), but
on the other hand they would have to be antiparticles. Interference
would have to involve certain frequencies and certain particles.

Antimatter

Artificially generated by crew or by aliens. Generated to power warp engines. May
occur naturally in real life. Matter
whose electrical charge properties are the opposite of "normal matter." It is
not yet well understood why the universe is made overwhelmingly of matter yet most
reactions which produce particles produce matter and antimatter equally. The
imbalance could have started as a minor percentage in the early moments of the
Big Bang, with resulting annihilation keeping the excess only (the rest is the
photon background).

TNG, DS9, VOY, ENT: countless episodes - Used to power the warp engines on Federation (and other) vessels.
Also used as explosive in photon torpedoes. Mentioned in countless episodes in all the series.
Star Trek quite correctly and consistently describes that antimatter,
if not contained, annihilates with matter in an uncontrolled
fashion.

DS9: "Business as Usual": Quark's
options on Antimonium became worthless in 2373.

Antineutrino

Naturally occurring or artificially generated by
aliens. A particle. In real life, a
by-product of beta decay.

VOY: "Prime Factors" - After B'Elanna installed the
Sikarian space-folding mechanism, the device generated antineutrino
particles as a part of the process of its normal operation. These particles
proved harmful to the Federation warp core and almost caused a core breach.
Fortunately B'Elanna thought quickly and phasered the device out of
existence before any serious harm was done.

Antineutron

Naturally occurring. A particle. A real particle; the antimatter version of a neutron.

"Star Trek: The Voyage Home" - Computer prompts Spock to
"adjust
the sine wave in the gravity envelope so that antineutrons may pass but
antigravitons cannot".

Antiproton

Naturally occurring. Also generated by ships; can penetrate Romulan
cloaking devices. In real life, the antimatter version of a proton. It
doesn't look as if all the mentioned antiprotons of Star Trek could be really
antiparticles.

DS9: "The Search, part 1"
- Used by the Jem'Hadar to detect the cloaked
Defiant.

DS9: "Defiant"
- Used by the Cardassians to detect the cloaked
Defiant.

TNG: "Face of the Enemy" - Enterprise-D used it to determine
who destroyed the smuggler's ship

TNG: "Silicon Avatar" - Crystalline Entity is tracked by
gamma radiation from antiproton decay. A real life experiment looking to see
whether antiprotons do decay by emitting gammas can be viewed at http://fnapx1.fnal.gov/.

VOY: "Threshold" - Used to slow down the mutation of
Lt. Paris' DNA.

"Star Trek: First Contact" - The navigational deflector of the
Enterprise-E normally stores a large number of antiprotons.

Antithoron

Artificially generated by aliens. Obviously the
antiparticles of thorons. Thorons are an
actual isotope. In Star Trek, it seems *anything* can suddenly become Anti. They must love that
prefix.

VOY: "Tattoo" - Antithoron
radiation is used to decontaminate a planetary crust prior to the
excavation of polyferranide.

VOY:
"Hunters" - Voyager has a antithoron system and produces a level- 8
antithoron burst to strengthen the gravitational pull of the quantum singularity inside a Hirogen communication relay by weakening the station's containment field. The resulting power release disables all of the relay network. The usage in this episode seems very contrary to the uses in previous episodes
involving regular
thorons. Submitted by Derek Seewald

Antitime

Origin unknown. Analogous to "antimatter" but for time, not matter.

TNG: "All Good Things" - Produced as a result of the time
rupture, which was caused by three dechyon beams from different timeframes
intersecting.

Anyon

Artificially generated by crew. Caused by the interaction between phased
and normal matter. In real life, an anyon isn't a real particle, it's a
theoretical construct formed by confining a normal fermion (and possibly
boson) to a two-dimensional region. The exchange arguments which lead to the
parity operator eigenvalues being +/-1 no longer apply, and these theoretical
constructs can have arbitrary quantum phase changes under exchange.

TNG: "The Next Phase" - Data hypothesized
that the bursts of
anyons were caused by phased matter. When Geordi and Ro set off a disruptor
on overload, a huge burst of anyons were detected, leading Data to sweep the
area with amnions and save Geordi and Ro.

Argine

Artificially generated by aliens. Possibly an
explosive. It is very
unlikely that this could be an argon compound.

DS9: "The Nagus" - Used in the construction of Ferengi
locator bombs.

Argonite

Origin unknown. Function unknown. It is very
unlikely that this could be an argon compound.

DS9: "Dr. Bashir, I Presume?" -
Argonite is said to be a hazardous substance.

Naturally occurring. They accumulate in a starship
after prolonged missions. In real life, "heavy" particles like protons, as
opposed to "light" particles (leptons) like electrons.

TNG: "Starship Mine" - The ship needed to undergo a "baryon
sweep" to remove the accumulation of these particles. It is obvious that
not much of the ship would be left, once the baryons were removed. So the
baryon sweep must be something very different or just an inaccurate
nickname for a procedure that removes certain types of baryons.

Benjisidrine

Artificially generated by aliens. Drug used by the
Vulcans against heart diseases.

Naturally occurring or generated by aliens. Nature unknown. Harmful or fatal to humans.

TOS: "This Side of Paradise" - The emotion-affecting spores
granted immunity to Berthold rays, allowing a colony to survive. Yes,
this seems to be the first occurrence of "immunity to radiation"
in Star Trek! A recurring phenomenon (unfortunately).

TNG: "Déjà Q" - A method employed by the
Calamarain to scan the Enterprise- D when the aliens were looking for Q.

Berylite
scan

Artificially generated by crew. A medical
procedure.

TNG: "A Matter of Time" -
Mentioned in this episode. A berylite scan obviously involves something
called "berylite", but it's not known whether the scan beam is
composed of
berylite or whether it scans for this substance.

Beta radiation

Naturally
occurring.
Beta radiation is released during beta decay and consists of electrons, such an electron was prior emitted by a neutron that
was converted to a proton, this process is called beta decay.

DS9: "Little Green Men" - Rom supposed that beta radiation
was responsible for the translator failure that hindered them from understanding the humans in 1947. Ferengi translators seem to react
quite hypersensitively to electrons, so better keep them away from electric currents (static electricity too, so better don't walk on carpets when you use one).

TNG: "The First Duty" - Wesley
Crusher is allergic to metorapan
treatments, so he is treated with a bicaridine substitute instead.

Bilitrium

Naturally occurring. A rare crystalline element which can be an incredible
source of energy if hooked up to an antimatter converter.

DS9: "Past Prologue" - Tahna Los had purchased a cylinder of
bilitrium from the Duras Sisters in an effort to destroy the wormhole.

Biogenic field/weapon

Naturally occurring or artificially generated by
crew. A form of energy, also used as a weapon. Well,
"biogenic" means "life-forming", isn't that an awful
euphemism?

TNG: "Preemptive Strike" - The
Maquis believed that the Cardassians were building biogenic weapons,
composed of "biomimetic gel, retroviral vaccines, isomiotic hypos and
plasma flares". That sounds as if it were possible to *store* a
flare...

DS9: "For the Uniform" - Cobalt
diselenide is a biogenic weapon. This statement is in strong contrast
to the one from TNG: "Preemptive Strike", where a biogenic
weapon was a very complex combination of different, partially genetically
engineered substances, whereas here the same can be achieved with a simple
anorganic compound.

VOY: "Sacred Ground" - A biogenic field was present at
one of the religious shrines of the Nechani.

Biomimetic
gel

Artificially generated by crew or by aliens. A
dangerous and highly illegal substance.

TNG: "Force of Nature" -
Biomimetic gel in large amounts was carried by the disappeared USS
Fleming. Well, what is Starfleet doing with large amounts of an illegal
substance?

TNG: "Preemptive Strike" -
Biomimetic gel is an ingredient for the production of biogenic weapons.

DS9: "Distant Voices" - Dr. Bashir
becomes suspicious when Quark asks for biomimetic gel for a customer. The
substance is outlawed in the Federation under very strict laws.

Bioneural
energy

Naturally occurring. Denotes electrical brain
activity.

VOY: "Cathexis" - Commander
Chakotay's bioneural energy (or his consciousness) was able to control
other lifeforms.

Bioplast

Artificially generated by
crew. Androids like Data contain this substance. Maybe it's produced by the same people that invented steelplast. ;)

TNG: "Time's Arrow, part I" -
Bitanium was used for Data's neural pathways.

Bitrium

Naturally occurring. Nature unknown.

TNG: "The Silicon Avatar" - Bitrous fibers were found on
planet after the Crystalline Entity had left. The crew theorized that bitrium
was a byproduct of the consumption of biological matter. Although its
name sounds like an element, I assume that bitrium is an organic compound,
since this would make a lot more sense here.

Borathium

Artificially generated by crew.
Experimental pharmaceutical, not yet released for common medical use in 2368.

TNG: "Ethics" - Toby Russell treated a patient with this substance instead of leporazin or morathial. Doctor Crusher regarded this incident as
a violation of medical ethics.

Artificially generated by crew. Experimental pharmaceutical in 2404 which protects organic tissues against tachyon radiation.
This effect points to something which we already know as inoculation against
radiation, however, although the term "inoculation against radiation" is a bit strange, it is possible (at least in the far future) to develop substances that make e.g. body cells
resistant against particles released as radiation, by either simply cover and
therefore shielding cellular membranes or accelerating the repair of cells.

VOY: "Endgame" - Admiral Janeway wanted Doctor "Joe" (the Holodoc) to supply her with these substance before she was going to return to her own past. This happened in an alternative future which ceased to exist, but it's still possible that it will be invented.

Artificially generated by crew and by aliens. Involved in time travel and in
cloaking; exact nature unknown.

TNG: "The Next Phase" - Chroniton particles from a
malfunctioning cloaking device cause Geordi and Ro to be phased so they can
pass through walls (not floors).

DS9: "Visionary" - Sent O'Brien back and forth in time
whenever a cloaked warbird came near DS9.

DS9: "Past Tense" - Used to travel back to 21st-century
Earth.

DS9: "The Assignment" - A Pah-Wraith who was going to destroy the wormhole with a chroniton beam,
was killed by this beam himself.

VOY: "Before and After" - When Kes was irradiated with
chroniton particles from the Krenim and later subjected to a biotemporal
field, she began to shift backwards in time.

Chronometric particle

Artificially generated by crew and by aliens. Involved in time travel.
There is no clue how this particle is different from a chroniton. Just like
the prefix "iso-", the appendix "-metric" is quite popular
to make something sound more sophisticated.

"Star Trek: First Contact" - The Borg used them to travel back in
time. The Enterprise-E used them to travel forward in time.

DS9: "Trials and Tribble-ations" - O'Brien reads chronometric
particles around the Defiant just before it is pulled back in time by the
Orb.

Cobalt
diselenide

Artificially generated by crew. A chemical compound that is considered a
biogenic weapon. Cobalt diselenide is harmless to most humanoids but is lethal
to Cardassians. If that is supposed to be CoSe2, it doesn't look
feasible to me.

DS9: "For the Uniform" - The Maquis, under the leadership of
Mr. Eddington, contaminated Cardassian colonies in the demilitarized zone
with cobalt desalinate to force them to abandon the planets.

Naturally occurring. A string of particles with gravitational forces that
are the strength of a black hole. It is a matter of perspective whether
this is to classify as particle or energy.

TNG: "The Loss" - A flurry of energy based entities
surrounding the Enterprise-D were headed for it, dragging the ship toward
certain destruction. These creatures disabled counselor Troi's empathic
powers for a time. The cosmic string was home to them.

Cryptobiolin

Artificially generated by aliens. An alien equivalent of steroids.

TNG: "The Hunted" - During a checkup on Roga Danar, Beverly
discovered high levels of cryptobiolin and other drugs in Danar's body.

TNG: "The Child" - According to Data,
Eichner radiation,
which caused genetically altered spores in stasis cage to expand
uncontrollably and threaten Enterprise, is released by "certain
cyanoacrylates". This is quite obvious and quite open nonsense,
and should be taken with a grain of salt.

Cytoglobin

Artificially generated by aliens.
Important medicine on the Dinaal hospital ship. "Globin" is the name of the protein component in haemoglobin (the red substance in the blood). "cyto" refers to body cells.

VOY: "Critical Care" - The Holodoc
administered a cytoglobin injection to a patient who would have died otherwise.

Naturally occurring. Causes phase shifts in normal matter.
In real life, dark matter is a concept to explain away the fact that there
should be more mass in the universe than is visible.

TNG: "In Theory" - Opened the wall for Spot to escape,
wrecked the conference room, and dematerialized part of the floor, causing
the death of a crewmember who walked into the "hole." Of course, the real
dark matter is just a concept. It could consist of any kind of matter (or
antimatter), while in the TNG episode it does have some very specific
properties, which is why I am classifying it as particles.

Dekyon

Artificially generated by crew. A particle with
exotic properties. In real life, de*ch*yons are the class of
particles that travel below the speed of light (i.e., the opposite of
tachyons).

VOY: "Parallax" - Used to open a fissure in an event
horizon. It clearly isn't possible to open such a fissure, unless one
were using enormous amounts of mass or maybe extremely exotic particles.
But definitely not just an otherwise undefined collection of
"ordinary" dechyons.

TNG: "Cause and Effect" - The crew detected these particles
as remnants of each "causality loop" and Data used them to send a message
into the next loop, which allowed them to break this most vicious cycle.

Delta
radiation

Generated by crew. Type of radiation produced by older
engines. Radiation of that name exists in
real life. Delta rays refer to moderate energy electrons which have been
kicked off a nucleus by the passage of a nearby high energy charged particle -
nothing to be much afraid of.

TOS: "The Menagerie, part I" - Was emitted from a broken piece
of an old starship. Christopher Pike, former captain of Starship
Enterprise, was overexposed in that accident, leaving him almost completely
paralyzed in a wheelchair.

DS9: "Visionary" - O'Brien
absorbed a heavy dose of delta radiation, which allowed the tetryon
emissions from the Romulan warbird to shift him through time.

ENT: "Rajiin" - A burst of delta
radiation is supposed to help in the synthesis of Trellium-D.

ENT: "In a Mirror, Darkly" -
Mirror Trip's face is disfigured thanks to high doses of delta radiation. The
make-up is a homage to that of Christopher Pike in the TOS episode.

Dentarium

Artificially generated by aliens.
Metal alloy, used by Vulcans in the construction of starships. Supplement
by Bernd: Sounds rather like something used by dentists.

DS9: "Duet" - Marritza was using the plasticine to preserve
his appearance as Gul Darhe'el.

Deuranium

Artificially generated by crew.
Metal alloy, used in starship construction. Supplement by Bernd:
Considering the cheesy writing of this episode, I have the impression they
thought of duranium, but didn't get it right.

VOY: "Threshold" - Deuranium was indented
to strengthen the nacelles of the Warp 10 shuttle, but it was later regarded as too brittle.

DS9: "The Passenger" - The Kobliad need deuridium to
stabilize their cell membranes in order to survive. It may be a bit more
plausible as a compound, but I'm keeping it as an element until more
evidence is found.

Deuterium

Naturally occurring. Used to power warp and impulse
drives. Isotope of hydrogen with an additional neutron. Deuterium has twice the mass of ordinary
hydrogen and is also called heavy hydrogen. Deuterium was discovered in 1931 by Harold Clayton Urey, a chemist at Columbia University, for which he earned the Nobel
Prize in chemistry in 1934.
It is useful in nuclear fusion reactions, as is tritium, because of the larger rate of reaction.
Deuterium can replace the normal hydrogen in water molecules to form heavy water
(D2O), which was a source of some concern during World War II, as Germany was known to be conducting experiments using heavy water as a nuclear reactor moderator, which might allow them to produce plutonium for an atomic bomb.
Deuterium is frequently used in chemistry and biochemistry as a tracer molecule to study reaction pathways because chemically it behaves identically to ordinary hydrogen, but it can be distinguished from ordinary hydrogen by its mass. Also, because of its greater mass, chemical reactions involving deuterium tend to occur at a slower rate than the corresponding reactions involving ordinary hydrogen.
It has been suggested that deuterium water (heavy water) should be considered toxic because if consumed in isolation it would displace light water and disturb the rate of biochemical reactions in the body.
Submitted by Daniel Welch

Countless episodes, including TNG: "Phantasms",
VOY: "Demon", VOY: "The Void" - Used to power the warp
core as well as impulse (fusion) reactors. Occurring in interstellar space,
it may be collected (with rather low efficiency) with the Bussard
collectors. Deuterium can be found in larger amounts in nebulae and on
planets.

ENT: "Marauders" - Deuterium is
"mined" on a planet and is very valuable. Decide for yourself
if you want to believe that...

Diboridium

Origin unknown. Material used by the Cardassians.

DS9: "Babel" - The aphasia-inducing device has a
diboridium
core which hints at possible Cardassian manufacture, but was actually
created by the Bajoran underground during the Cardassian occupation of
Bajor. Diboridium may stand for a combination of two boridium
atoms. But *Di*boridium would be meaningless since the element can be
supposed to have a crystalline
structure. Most likely diboridium is a different element than boridium analogous
to tricobalt and cobalt.

Diburnium
(unconfirmed)

Origin unknown. A metallic element. Considering
that there is a diburnium-osmium alloy too, diburnium is obviously an element.

TOS: "By Any Other Name "- The substance used by the
Kelvans
to imprison Captain Kirk and company in the cave was described by Spock as
"similar to diburnium, but much denser."

Diburnium-osmium alloy

Artificially generated by aliens. A substance highly resistant to energy
and radiation.

TOS: "That Which Survives" - An artificial planet was made of
this substance. The Kalandans were the race responsible.

Naturally occurring. An apparent element that makes up part of the molecular
structure of a gaseous creature, possibly allowing the creature to exist in a
state on the border between matter and energy and avoid weapons fire by moving
itself through time.

TOS: "Obsession" - Kirk encounters the gaseous creature while
prospecting for tritanium deposits. It gives of a sickly sweet odor, which
Kirk recognizes from another encounter with the creature eleven years before - an
encounter that resulted in the death of then Lieutenant Kirk's commanding
officer, Captain Garrovick, and a consequent load of guilt. Kirk and
Garrovick's son destroy the creature with an anti-matter bomb, since it is
immune to phasers and photon torpedoes.

Dilithium

Naturally occurring. Focuses energy into highly concentrated form.
Necessary for the operation of warp drives, and a vital part of a starship's
power system.

TOS: various, including "Mudd's
Women" and "Elaan of Troyius". Dilithium is used a power
source. This has been contradicted ever since the concept of the warp
core with its matter-antimatter reaction, where a dilithium crystal is
just the place where the power is generated.

TNG: "Relics" - La Forge states to an out-of-time Mr. Scott
that they recomposite the dilithium inside the reaction chamber. Only after
Mr. Scott erroneously states that dilithium crystals are going to fracture.

Countless episodes - Dilithium or a
"dilithium matrix" is mentioned as a part of the warp core.

Displacement wave

Artificially generated by aliens. Moves objects at
very high speed.

VOY: "The Caretaker" - Used by Caretaker to bring ships to
Delta Quadrant.

Disruptor beam

Artificially generated by aliens. Klingon equivalent of a phasers.
Accompanied by a shrill, echoing sound.

TOS: "Errand of Mercy" - Used by the Klingons to
retaliate against the Organians for acts of sabotage by Kirk and Spock.

TOS:
"Elaan of Troyius" - The
Klingons fired it the Enterprise during attacking runs in Elaan of Troyius.

TNG, DS9, VOY, ENT various episodes -
Mentioned as weapons of Klingons, Romulans and other aliens.

Dolamide

Origin unknown. Used in power generators, reactors, and short-range
transporters. If pure enough, it can be made into weapons.

DS9: "Dramatis Personae" - Kira refuses a Valerian transport
carrying dolamide to dock with the station under the suspicion that they are
trading with the Cardassians.

DS9: "Paradise" - Astatin deposits in the swamp beds near
Alixus' community prevented equipment from operating.

Drechtal
beam

Artificially generated by crew.
Beam used surgically to cut sensoric nerves in the brain. Instead of
recruiting yet another exotic particle, we could claim that it's a simple
specially shaped laser beam named for its inventor, Drechtal.

Artificially generated by crew. A hard metal
alloy used for the hull
of spacecrafts. A hard metal
alloy, or rather a pure metal? Most technically used metals are more or less
alloys, so the distinction may not be clear-cut.

TOS: "The Menagerie, part I" -
Duranium is used to build Federation shuttlecraft.

TNG: "Hollow Pursuits" - O'Brien tested the transporter with
a container made of pure duranium. The container rematerialized as molten
goo.

DS9: "The Emissary" - Duranium shadows were used to create an
illusion of photon torpedo launchers on DS9.

DS9: "Captive Pursuit" - Used in construction of access
tunnels on DS9; impervious to normal sensors.

DS9: "Q-Less" - The hull of a
Federation runabout is made of duranium.

DS9: "The Siege" - Used in
construction of access tunnels on DS9; impervious to normal sensors.

VOY: "Initiations" - Used for the
construction of Kazon vessels.

VOY: "Threshold" - The hull of the
shuttlecraft is composed of duranium.

ENT: "Dead Stop" - Duranium pins are used in the nacelles.
Submitted by George Cheng.

Duratanium

Artificially generated by crew. Very strong alloy used in construction of starship hulls or structural
augmentation.

VOY: "Dreadnaught" - Voyager encountered debris from a destroyed vessel made of duratanium.

ENT: "Breaking the Ice" - The comet contained eisillium.
This may be a German reference: the comet consisted mostly of ice (=Eis).
Only that we need to wonder since when Vulcans speak German, as the name of
the substance was used by Vulcans and unfamiliar to humans.

Naturally occurring or artificially generated by
crew or by aliens. A bioelectrical effect, used as an analysis method. In real life, electrophoresis is a process by which proteins are
identified by putting them on a gel and running an electric current through
the gel, then staining the gel and measuring how far the proteins moved in
comparison to a group of standard proteins that were also put on the gel
(bigger proteins move slower, in general).

"Star Trek: Generations" - The first known contact with the energy
ribbon (known as the "Nexus" to El-Aurians) was in 2293 when two ships transporting El-Aurian refugees were caught up by it. The just-christened USS Enterprise-B responded to the ships' distress calls despite being unprepared for service. Captain James T. Kirk, who was a guest aboard the Enterprise and had been implementing modifications to allow its escape, was lost into the Nexus when it struck and severely damaged the ship. At the time this was thought to be Kirk's death.

Submitted by Alex Golden

Epsilon radiation

Naturally
occurring.
Uncommon toxic energy that is related to tetryon reactors. Could that be
another "misused" name of real-world radiation?